The present invention relates to a fluid operated wrench for tightening or loosening threaded connectors which for example connect a flange to a member or two flanges to each other.
Such wrenches are disclosed for instance in my U.S. Pat. Nos. 4,079,641 or 4,336,727. During tightening or loosening a threaded connector in which the nut is turned in one direction a reaction force is created which tends to turn the whole wrench in the opposite direction. To take up this reaction force, the wrenches as disclosed in the aforementioned patents are provided on its support with means for engaging a stationary member adjacent to the nut to be turned, which is usually a nut adjacent to that to be turned by the wrench, a flange adjacent to the nut to be turned etc. This engaging means is formed as a reaction plate connected to the support and engaging the stationary member with tremendous force. When the torsion force within the threaded connector which is opposite to the movement of the ratchet gear of the wrench during the active stroke is increased and forces the wrench when the ratchet gear is engaged against the reaction point, the wrench cannot be loosened and it has to be partially destroyed to be taken off the nut. It is to be understood that this operation is very complicated and connected with undesirable damage to the wrench.